Method of fabricating organic electroluminescence display device comprising an elastic contact electrode

ABSTRACT

An organic electro-luminescence display device includes at least one light emission device, the organic light emission device having a first electrode; at least one thin film transistor for driving the light emission device, a pixel electrode being connected to the at least one thin film transistor; a conductive layer formed of a conductive polymer material to electrically connect the light emission device and the pixel electrode.

This application is a Divisional of application Ser. No. 11/417,017filed May 4, 2006 now U.S. Pat. No. 7,965,034 which application claimspriority under 35 U.S.C. §119(a) on Patent Application No.10-2005-0128041 filed in Korea on Dec. 22, 2005, the entire contents ofeach of which are hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an organic electroluminescence displaydevice, and more particularly to an organic electroluminescence displaydevice that is adaptive for solving an electric contacting defectproblem caused between a light emission array and a TFT array, and afabricating method thereof.

2. Description of the Related Art

Recently, various flat panel display devices have been developed toreduce the weight and size so as to replace a relatively heavy andlarge-size cathode ray tube. The flat panel display device includesliquid crystal display (LCD), field emission display (FED), plasmadisplay panel (PDP), electro-luminescence (EL) display device and so on.

The PDP has a relatively simple structure and fabrication process.Therefore, the PDP is most advantageous to be made large-sized, but ithas a disadvantage in that its light emission efficiency and brightnessare low and its power consumption is high. The manufacturing process forthe LCD is similar to the semiconductor process. Therefore, the LCD isdifficult to be made large-sized, and its power consumption is high dueto a backlight unit. Further, the LCD has a disadvantage in that itsviewing angle is narrow and there is a high light loss by opticaldevices such as a polarizing filter, a prism sheet, a diffusion plateand so on. In comparison, the EL display device has an advantage in thatits response speed is fast, its light emission efficiency and brightnessare high and its viewing angle is wide.

The EL display device is generally divided into an inorganic EL displaydevice and an organic EL display device in accordance with the usedmaterial.

The organic EL display device is driven with a low voltage of about5˜20[V] in comparison with the inorganic EL display device whichrequires a high voltage of 100˜200[V]. Therefore, it is possible todrive the organic EL display device with a low DC voltage. Further, theorganic EL display device can be used as a pixel of a surface lightsource, a television image display or a graphic display because theorganic EL display device has an excellent characteristic such as a wideviewing angle, a high speed response, a high contrast ratio and so on.In addition, the organic EL display has a good color impression and isthin and light. It is a suitable device for the next generation flatpanel display.

A method of driving the organic EL display device can be divided into apassive matrix type and an active matrix type.

The passive matrix type organic EL display device is simple in itsconfiguration so its fabricating method is also simple. However, thereis a disadvantage in that its power consumption is high, it is difficultto make a display device large-sized, and its aperture ratio isdeteriorated as the number of wire lines increases.

On the other hand, the active matrix type organic EL display device hasadvantages of high light emission efficiency and high picture qualityrealization.

Further, the organic EL display device can be divided into the TopEmission Type and the Bottom Emission Type in accordance with its lightemitting direction.

FIG. 1 is a diagram illustrating an example of the Top Emission Typeactive matrix organic EL display device in the related art.

Referring to FIG. 1, the Top Emission Type active matrix organic Eldisplay device of the related art includes a light emission array 30comprising a light emitting part formed on a first substrate 1; a TFTarray 40 comprising a thin film transistor TFT controlling the lightemitting part on a second substrate 2; and a contact part 50electrically connecting the light emission array 30 and the TFT array40. Further, the first and second substrates 1, 2 are bonded together bya sealant 60.

The light emission array 30 includes a color filter array, a firstelectrode 11, an organic light emitting layer 15 and a second electrode17 which are sequentially deposited on the first substrate 1. Further itincludes a barrier rib 13 which separates the organic light emittinglayer 15 and the second electrode 17 so as to be form the pixel area.

The color filter array includes a black matrix 3 which prevents lightleakage from a pixel and blocks an external light so as to increasecontrast ratio; a color filter 5 for realizing color; an auxiliary colorlayer (or CCM (color change method) layer) 7 for increasing a colorreproduction effect of the color filter 5; and an overcoat layer 9 forleveling the color filter array.

The organic light emitting layer 15 includes a holeinjecting/transporting layer 15A, a light emitting layer 15B and anelectron injecting/transporting layer 15C.

If a voltage is applied between the first electrode 11 and the secondelectrode 17, a hole generated from the first electrode moves toward thelight emitting layer 15B through the hole injecting/transporting layer15A. Further, an electron generated from the second electrode 17 movestoward the light emitting layer 15B through the electroninjecting/transporting layer 15C. Accordingly, the hole and electroncollide with each other in the light emitting layer 15B to bere-combined, thereby emitting the light. And, the light is emitted tothe outside through the color filter array so that a picture isdisplayed.

The TFT array 40 includes a semiconductor layer 4, a gate insulatingfilm 6, a gate electrode 8, an interlayer insulating film 10, source anddrain electrodes 12, 16, a passivation film 20, and a pixel electrode 22which are sequentially deposited on the second substrate 2.

As having the injected n+ impurities, the semiconductor layer 4 includesa source area, a drain area and a channel area formed between the sourcearea and the drain area. The semiconductor layer 4 properly furtherincludes an LDD (lightly doped drain) area, where n− impurities areinjected, between the channel area and the source and drain areas forreducing an off-current.

The gate electrode 8 is formed to overlap the channel area of thesemiconductor layer 4 with the gate insulating film 6. The source anddrain electrodes 12, 16 are formed to be insulated with the gateelectrode 8 by the interlayer insulating film 10 therebetween. Thesource and drain electrodes 12, 16 are respectively connected to thesource and drain areas of the semiconductor layer 4 through a sourcecontact hole 14 and a drain contact hole 18 which penetrate the gateinsulating film 6 and the interlayer insulating film 10.

The pixel electrode 22 is connected to the drain electrode 16 throughthe pixel contact hole 24 which penetrates the passivation film 20.

The light emission array 30 and the TFT array 40 are electricallycontacted with each other through a contact part 50. The contact part 50includes a contact supporting part 52 and a contact electrode 54. Thecontact supporting part 52 is formed of a photo-resist pattern. Thecontact electrode 54 is formed by a mask process to cover the pixelelectrode 22 and the contact supporting part 52, and is contacted withthe second electrode 17 of the light emission array 30 when bonding thefirst and second substrates 1, 2, thereby electrically connecting thelight emission array 30 and the TFT array 40.

The contact electrode 54 is comprised of a metal material such asaluminum (Al), molybdenum (Mo), chrome (Cr) and so on. In addition, thesecond electrode 17 of the emission array 30 is also comprised of themetal material. Therefore, the contacting adhesion between the contactelectrode 54 and the second electrode 17 is weak. Therefore, it maycause an electric contacting problem that a signal from the TFT array 40is not properly supplied to the second electrode 17. Further, in casethat the photo-resist pattern is not formed in a uniform thickness whenforming the contact supporting part 52, the contacting defect problemmight be generated because the contact electrode 54 formed on thecontact supporting part 52 is thin and may not be in contact with thesecond electrode 17 of the light emission array 30. Because the contactsupporting part 52, the contact electrode 54 and the second electrode 17are all rigid material such as metal, when joining the contact electrode54 and the second electrode 17, it is hard to completely contact thesecond electrodes 17 with the contact electrodes 54 over the entiresubstrate area. Because it is hard to form the all contact supportingpart 52 and the contact electrode 54 to have the exactly same height, agap may be generated between some contact electrodes 54 and thecorresponding second electrodes 17, which causes the contact defect.

SUMMARY OF THE INVENTION

Accordingly, it is one of the objects of the present invention toprovide an organic electroluminescence display device that is adaptivefor solving a contacting defect problem caused between a light emissionarray and a TFT array, and a fabricating method thereof.

It is another one of the objects of the present invention to provide anorganic electroluminescence display device that has a contact electrodewith elasticity so as to be completely contacted with the electrode ofthe light emission array by pressing.

In order to achieve these and other objects of the invention, an organicelectro-luminescence display device as embodied in the present inventionincludes a light emission array having a color filter array and anorganic light emitting layer on a first substrate; a thin filmtransistor array on a second substrate for controlling the lightemission array; and a contact electrode formed of a conductive polymermaterial to electrically connect the light emission array and the thinfilm transistor array.

In another aspect of the present invention, a method of fabricating anorganic electroluminescence display device, as embodied in the presentinvention, includes providing first and second substrates; forming alight emission array including a color filter array and an organic lightemitting layer on the first substrate; forming a thin film transistorarray on the second substrate for controlling the light emission array;and forming a contact electrode which includes a conductive polymermaterial for electrically connecting the light emission array and thethin film transistor array.

In another aspect of the present invention, an organicelectro-luminescence display device, as embodied in the presentinvention, includes at least one light emission device, the lightemission device having a first electrode; at least one thin filmtransistor for driving the light emission device, the at least one thinfilm transistor being connected to a pixel electrode; a conductive layerformed of a conductive polymer material to electrically connect thelight emission device and the pixel electrode.

In another aspect of the present invention, a method of fabricating anorganic electroluminescence display device, as embodied in the presentinvention, includes forming at least one light emission device having afirst electrode; forming at least one thin film transistor for drivingthe light emission device; forming a pixel electrode connected to the atleast one thin film transistor; forming a conductive layer formed of aconductive polymer material to electrically connect the light emissiondevice and the pixel electrode.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other objects of the invention will be apparent from thefollowing detailed description of the embodiments of the presentinvention with reference to the accompanying drawings, in which:

FIG. 1 is a diagram illustrating a Top Emission Type active matrixorganic electroluminescence display device of the related art;

FIG. 2 is a diagram illustrating a Top Emission Type active matrixorganic electroluminescence display device according to an embodiment ofthe present invention;

FIGS. 3A to 3F are diagrams illustrating a fabrication process of alight emission array shown in FIG. 2;

FIGS. 4A to 4G are diagrams illustrating a fabrication process of a TFTarray shown in FIG. 2;

FIG. 5 is a diagram illustrating the formation of a contact supportingpart shown in FIG. 2;

FIGS. 6A to 6C are diagrams illustrating a first embodiment of forming acontact electrode shown in FIG. 2; and

FIGS. 7A to 7C are diagrams illustrating a second embodiment of forminga contact electrode shown in FIG. 2.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

Reference will now be made in detail to the preferred embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings.

With reference to FIGS. 2 to 7C, embodiments of the present inventionwill be explained as follows.

FIG. 2 is a diagram illustrating a Top Emission Type active matrixorganic electroluminescence display device according to an embodiment ofthe present invention.

Referring to FIG. 2, the organic electroluminescence display deviceaccording to an embodiment of the present invention includes a lightemission array 130 where a light emitting part is formed on a firstsubstrate 101; a TFT array 140 where a thin film transistor TFTcontrolling the light emitting part is formed on a second substrate 102;and a contact part 150 which electrically connects the light emissionarray 130 and the TFT array 140. The first and second substrates 101,102 are bonded together by a sealant 160.

The light emission array 130 includes a color filter array, a firstelectrode 111, an organic light emitting layer 115 and a secondelectrode 117 which are sequentially deposited in the first substrate101, and further includes a barrier rib 113 which separates the organiclight emitting layer 115 and the second electrode 117 so as to form apixel area.

The color filter array includes a black matrix 103 which prevents lightleakage from a pixel and blocks/absorbs an external light so as toincrease contrast ratio; a color filter 105 for realizing color; anauxiliary color layer (or CCM (color change method) layer) 107 forincreasing a color reproduction effect of the color filter 105; and anovercoat layer 109 for leveling the color filter array.

The organic light emitting layer 115 includes a holeinjecting/transporting layer 115A, a light emitting layer 115B and anelectron injecting/transporting layer 115C.

If a voltage is applied between the first electrode 111 and the secondelectrode 117, a hole generated from the first electrode 111 movestoward the light emitting layer 115B through the holeinjecting/transporting layer 115A. Further, an electron generated fromthe second electrode 117 moves toward the light emitting layer 115Bthrough the electron injecting/transporting layer 115C. Accordingly, thehole and electron collide with each other in the light emitting layer115B to be re-combined, thereby emitting the light. The light is emittedto the outside through the color filter array to display a picture.

The TFT array 140 includes a semiconductor layer 104, a gate insulatingfilm 106, a gate electrode 108, an interlayer insulating film 110,source and drain electrodes 112, 116, a passivation film 120, and apixel electrode 122 which are sequentially deposited in the secondsubstrate 102.

By injecting the n+ impurities, the semiconductor layer 104 includes asource area, a drain area and a channel area formed between the sourcearea and the drain area. And, the semiconductor layer 104 might furtherinclude an LDD (lightly doped drain) area, where n− impurities areinjected, between the channel area and the source and drain areas forreducing an off-current.

The gate electrode 108 is formed to overlap the channel area of thesemiconductor layer 104 with the gate insulating film 106. The sourceand drain electrodes 112, 116 are formed to be insulated with the gateelectrode 108 with the interlayer insulating film 110 therebetween. Thesource and drain electrodes 112, 116 are respectively connected to thesource and drain areas of the semiconductor layer 104 through a sourcecontact hole 114 and a drain contact hole 118 which penetrate the gateinsulating film 106 and the interlayer insulating film 110.

The pixel electrode 122 is connected to the drain electrode 116 throughthe pixel contact hole 124 which penetrates the passivation film 120.

The light emission array 130 and the TFT array 140 are electricallycontacted with each other through a contact part 150. The contact part150 includes a contact supporting part 152 and a contact electrode 154.The contact supporting part 152 is formed by a photolithography processusing a photo-resist pattern of metal material. The contact electrode154 is formed to cover the contact supporting part 152 and part of thepixel electrode 122 by use of a material such as polyaniline,polypyrole, polythiopene and so on. Further, the contact electrode 154is in contact with the second electrode 117 of the light emission array130 when bonding the first and second substrates 101, 102, therebyelectrically connecting the light emission array 130 and the TFT array140.

The fabricating method of the organic electroluminescence display deviceaccording to an embodiment of the present invention including a methodof forming the contact electrode 154 will be explained in reference toFIGS. 3A to 3F. FIGS. 3A to 3F are diagrams shown by inverting an upperpart and a lower part of the light emission array 130 shown in FIG. 2 inorder to explain the fabrication process of the light emission array 130shown in FIG. 2.

Referring to FIG. 3, an opaque material is patterned by aphotolithography process using a mask and an etching process after theopaque material is deposited in the first substrate 101, thereby formingthe black matrix 103.

A photosensitive red resin R is deposited on the entire surface of thefirst substrate 101 where the black matrix 103 is formed. A mask havingan exposure area and a shielding area is aligned on the first substrate101 where the red resin R is deposited. Subsequently, the red resin Rexposed through an exposure area by a photolithography process using amask and an etching process is removed and the red resin R which is notexposed through a shielding, area remains, thereby forming a red colorfilter 105R.

A green resin G is deposited on the entire surface of the firstsubstrate 101 where the red color filter 105R is formed. The same maskprocess as the process of forming the red color filter 105R is repeated,thereby forming a green color filter 105G.

A blue resin B is deposited on the entire surface of the first substrate101 where the green color filter 105G is formed. The same mask processas the process of forming the red and green color filters 105R, 105G isrepeated, thereby forming a blue color filter 105B. At this moment, gapsbetween the adjacent blue, green and red color filters 105B, 105R, 105Gare each set to be about 5 μm to 7 μm with the black matrix 103therebetween.

An auxiliary color layer 107 is formed on the color filter 105 which isformed through such a process. The auxiliary color layer 107 is formedto correspond to the color filter 105, thereby acting to increase acolor reproduction of the color filter 105.

A transparent resin with an insulating characteristic is spread on thefirst substrate 101 where the auxiliary color layer 107 is formed,thereby forming an overcoat layer 109, as shown in FIG. 3B.

The transparent electrode material is deposited on the entire surface ofthe first substrate 101 where the overcoat layer 19 is formed, by adeposition method such as sputtering, etc, thereby forming the firstelectrode 111, as shown in FIG. 3C. The transparent electrode materialin use is indium tin oxide (ITO), tin oxide (TO) or indium zinc oxide(IZO).

An insulating material is patterned by a photolithography process and anetching process after depositing or spreading an organic or inorganicinsulating material on the first substrate 101 where the first electrode111 is formed, thereby forming a barrier rib 113, as shown in FIG. 3D.The barrier rib 113 has a reverse taper structure so that the organiclight emitting layer formed later on can be separated. Even though notshown in the diagram, an insulating film can further be formed betweenthe first electrode 111 and the barrier rib 113.

Subsequently, as shown in FIG. 3E, the organic light emitting layer 115corresponding to each color filter 105 area is formed on the firstsubstrate 101 where the barrier rib 113 is formed. At this moment, theorganic light emitting layer 115 can be configured to be single-layeredor multi-layered. In case of being configured to be multi-layered, thehole injecting/transporting layer 115A, the light emitting layer 115B,and the electron injecting/transporting layer 115C are sequentiallyformed.

A second electrode 117 is formed by a deposition method such assputtering on the first substrate 101 where the organic light emittinglayer 115 is formed, as shown in FIG. 3F. The second electrode 117 canbe formed by use of one of aluminum (Al), calcium (Ca) and magnesium(Mg). It can also be formed in a double metal layer of lithiumfluorine/aluminum (LIF/Al) or as the like.

FIGS. 4A to 4G are diagrams illustrating a fabrication process of a TFTarray 140 shown in FIG. 2.

First, referring to FIG. 4A, a poly crystalline silicon layer is formedby a dehydrogenation process and a crystallization process using heatafter depositing an amorphous silicon on the second substrate 102, andthe silicon layer is patterned by a photolithography process using amask and an etching process, thereby forming the semiconductor layer104.

The semiconductor layer 104 is defined as a source area, a drain areaand a channel area formed between the source area and the drain area.

A buffer layer including at least one of silicon nitride and siliconoxide (though not shown in the diagram) might be formed between thesecond substrate 102 and the semiconductor layer 104.

The gate insulating film 106 is formed by use of an insulating materialsuch as silicon nitride and silicon oxide, as shown in FIG. 4B, on thesecond substrate 102 where the semiconductor layer 104 is formed.

A gate metal material is patterned by a photolithography process using amask and an etching process after depositing a gate metal material by adeposition method such as sputtering on the second substrate 102 wherethe gate insulating film 106 is formed, thereby forming the gateelectrode 108, as shown in FIG. 4C. And then, impurities are injected toform a source area and a drain area of the semiconductor layer 104. Thegate metal material is a conductive metal including at least one ofaluminum (Al), aluminum alloy, copper (Cu), tungsten (W), tantalum (Ta)and molybdenum (Mo).

An insulating material is formed by a photolithography process using amask and an etching process after depositing the insulating material onthe second substrate 102 where the gate electrode 108 is formed. Theinterlayer insulating film 110 including the source and drain contactholes 114, 118 which expose the source and drain areas of thesemiconductor layer 104, is formed as shown in FIG. 4D.

Subsequently, a source and drain metal layer is patterned by aphotolithography process using a mask and an etching process afterdepositing the source and drain metal layer by the deposition methodsuch as sputtering on the second substrate 102 where the interlayerinsulating film 110 is formed. The source electrode 112 and the drainelectrode 116 which are respectively in contact with the source area anddrain area of the semiconductor layer 104, are formed as shown in FIG.4E. At this moment, the source electrode 112 and the drain electrode 116are each in contact with the semiconductor layer 104 through the sourcecontact hole 114 and the drain contact hole 118.

The insulating material is patterned by a photolithography process andan etching process after depositing the insulating material on thesecond substrate 102 where the source and the drain electrodes 112, 116are formed. The passivation film 120 having the pixel contact hole 124which exposes the drain electrode 116, is formed as shown in FIG. 4F.

The conductive metal is patterned by a photolithography process and anetching process after depositing the conductive metal on the secondsubstrate 102 where the passivation film 120 is formed. The pixelelectrode 122 which is in contact with the drain electrode 116, isformed as shown in FIG. 4G. At this moment, the pixel electrode 122 isin contact with the drain electrode 116 through the pixel contact hole124.

The photo-resist pattern is formed on the pixel electrode 122 of the TFTarray 140 formed by such a process, thereby forming the contactsupporting part 152, as shown in FIG. 5.

FIGS. 6A to 6C are diagrams illustrating a first embodiment of forming acontact electrode 154 on the contact supporting part 152.

At first, referring to FIG. 6A, a conductive polymer 172 is sprayed by aspreading process such as nozzle spray, spin coating or the like on theTFT array 140 where the contact supporting part 152 is formed. Theconductive polymer 172 comprises of at least selected one ofpolyaniline, polypyrole, polythiopene and so on. In this embodiment,there is used a molding technique of solidifying to form a shape with asoft mold 174. The conductive polymer material can be used by beingmixed with a polymer material which can be hardened by heat, UV or amono-acryl.

After aligning the soft mold 174 on the spread conductive polymer 172,as shown in FIG. 6B, the soft mold 174 is pressed slightly. For example,the soft mold 174 can be pressed by its own weight. Then, the soft mold174 can exactly contact to the top surface of the TFT array 140.

The soft mold 174 is made from a rubber material with high elasticitysuch as polydimethylsiloxane (PDMS), polyurethane or cross-linkedNovolac resin. There is a groove 171 corresponding to a pattern whichmakes the conductive polymer 172 remain on the TFT array 140, i.e., apattern which electrically connects the pixel electrode 122 of the TFTarray 140 with the second electrode 117 of the light emission area 30.Herein, the typical soft mold 174 is proposed in the Korean PatentApplication No. 2003-0098122 which is pre-applied by this applicant ofthe present invention. The soft mold is surface-treated to have thehydrophobic or the hydrophilic property. In an embodiment of the presentinvention, the soft mold is treated to have a repulsive property againstthe conductive polymer 172.

The conductive polymer 172 is gathered into a space formed between thecontact supporting part 152 and the groove 171 of the soft mold 174 by acapillary force generated by a pressure between the soft mold 174 andthe TFT array 140 and a repulsive force between the soft mold 174 andthe conductive polymer 172, as shown in FIG. 6B. As a result, theconductive polymer 172 pattern is formed on the TFT array 140 in apattern shape of being transferred inversely to the groove 171 patternof the soft mold 174. Specifically, the conductive polymer 172 patterncovers the contact supporting part 152 on the TFT array 140 and isformed in a part which is in contact with the pixel electrode 122.

After solidifying the conductive polymer 172 pattern by use of athermosetting process, a light curing process through a photopolymerization reaction process or a temperature-applying treatment, thesoft mold 174 is separated from the TFT array 140. Then, the contactelectrode 154 is formed of the conductive polymer 172, as shown in FIG.6C.

FIGS. 7A to 7C are diagrams illustrating a second embodiment of formingthe contact electrode 154 on the contact supporting part 152.

At first, referring to FIG. 7A, the conductive polymer 172 is disposedby a supply roller 176 where the conductive polymer 172 is spread on thesurface thereof on the contact supporting part 152 where the TFT array140 is formed. The conductive polymer 172 used in the second embodimentcomprises at least selected one of plyaniline, polypyrole, polythiopene,and so one in the same manner as the first embodiment. However, thisembodiment uses a printing technique and solidifies the conductivepolymer material of high viscosity within a short time after spreadingthe conductive polymer material. The conductive polymer material can bemixed with an organic solvent of an alcohol group which can be easilyvaporized.

Heat is applied to the conductive polymer 172 disposed on the contactsupporting part 152 at not less than a glass transition temperature ofthe conductive polymer which remains in a state where the solvent isremoved (vaporized), as shown in FIG. 7B. Then, the conductive polymer172 is softened by the heat so as to flow down completely covering thecontact supporting part 152, thereby being in contact with the pixelelectrode 122 of the TFT array 140. Accordingly, the contact electrode154 of the conductive polymer 172 is formed, as shown in FIG. 7C.

The light emission area 130 and the TFT array 140 formed in this way arebonded by the sealant 160 spread between the first substrate 101 and thesecond substrate 102, as in FIG. 2, so as to be electrically connectedthrough the contact part 150. At this moment, the contact electrode 154of the contact part 150 formed on the pixel electrode 122 of the TFTarray 140 is formed of the conductive polymer, thereby having a lowsurface energy. And, the second electrode 117 of the light emissionarray 130 is formed of a metal material, thereby having a high surfaceenergy. Thus, the adhesive force is greatly improved than the relatedart where the contact electrode 154 and the second electrode 117 are allformed of the metal material. Further, the risk of the causing thecontact defect is low even if there is a thickness difference betweenthe contact parts 150 when being in contact with the second electrode117 of the light emission array 130 due to the elastic characteristic ofthe conductive polymer. In addition, the contacting area is increased toimprove the contact therebetween.

In addition, in the method of forming the contact electrode 154 in therelated art, the mask process is used. Therefore, there is a problem inthat the required time for process is long, the photo-resist materialand stripping solution are wasted, and expensive equipments such asexposure equipment and so on are needed. However, no mask process isrequired in the illustrated embodiments of the present invention.Therefore, the fabrication process is simplified and the cost is reducedin comparison with the related art.

As described above, the organic electro-luminescence display device andthe fabricating method thereof according to the illustrated embodimentsof the present invention form the contact electrode by use of theconductive polymer material. Therefore, the contact surface can beperfectly in contact so as to generate no contact defect when thecontact electrode is in contact with the second electrode of the lightemission area by the pressure upon bonding them because the contactelectrode which electrically connects the light emission array with theTFT array has ductility differently from the contact electrode of therelated art that is formed of a metal. Accordingly, in the contactelectrode according to the illustrated embodiments of the presentinvention, the wire breakage problem is reduced when being electricallyin contact with the second electrode of the light emission array.Further, the organic electroluminescence display device and thefabricating method thereof form the contact electrode by use of theconductive polymer material differently from the related art where thecontact electrode is formed of the metal by a photolithography process,thus the fabrication process is simplified and there is an effect ofreducing the cost.

Although the present invention has been explained by the embodimentsshown in the drawings described above, it should be understood to theordinary skilled person in the art that the invention is not limited tothe embodiments, but rather that various changes or modificationsthereof are possible without departing from the spirit of the invention.Accordingly, the scope of the invention shall be determined only by theappended claims and their equivalents.

1. A method of fabricating an organic electroluminescence display devicecomprising a light emission array having a first and second electrodes,and an organic light emitting layer formed between the first and secondelectrodes, the method comprising: providing first and secondsubstrates; forming a light emission array including a color filterarray and an organic light emitting layer on the first substrate;forming a thin film transistor array on the second substrate forcontrolling the light emission array; and forming a contact electrodewhich includes a conductive polymer material for electrically connectingthe light emission array and the thin film transistor array, wherein theorganic light emitting layer includes a hole injecting/transportinglayer, a light emitting layer and an electron injecting/transportinglayer, wherein the contact electrode has an elasticity and a surfaceenergy lower than the second electrode, and wherein the second electrodeof the light emission array is formed between a electroninjecting/transporting layer and the contact electrode, and connected tothe contact electrode.
 2. The method according to claim 1, wherein thestep of forming the light emission array further comprises: forming acolor filter array on the first substrate; forming the first electrodeon the color filter array; forming the organic light emitting layer onthe first electrode; forming the second electrode on the organic lightemitting layer; and forming a barrier rib on the first electrode fordividing the organic light emitting layer and the second electrode todefine a pixel area.
 3. The method according to claim 2, wherein thestep of forming the color filter array further comprises: forming ablack matrix at a location corresponding to the barrier rib on the firstsubstrate; forming a plurality of color filters with the black matrixtherebetween; forming an auxiliary color layer on the color filters; andforming an overcoat layer on the first substrate where the auxiliarycolor layer is formed.
 4. The method according to claim 2, wherein thestep of forming the thin film transistor array further comprises:forming a semiconductor layer including a source area, a drain area anda channel area between the source area and the drain area on the secondsubstrate; forming a gate electrode overlapped with the channel area ofthe semiconductor layer with a gate insulating film therebetween;forming a source electrode connected to the source area of thesemiconductor layer through a source contact hole which penetrates thegate insulating film and an interlayer insulating film that is depositedon the gate insulating film; forming a drain electrode connected to thedrain area of the semiconductor layer through a drain contact hole whichpenetrates the gate insulating film and the interlayer insulating film;and forming a pixel electrode connected to the drain electrode through apixel contact hole which penetrates the interlayer insulating film and apassivation film that is deposited on the source electrode and the drainelectrode.
 5. The method according to claim 4, wherein the step offorming the contact electrode includes forming the contact electrode tobe in contact with the second electrode and the pixel electrode.
 6. Themethod according to claim 1, further comprising forming a contactsupporting part including a metal on the thin film transistor array,wherein the step of forming the contact electrode further comprisesforming the contact electrode on the contact supporting part.
 7. Themethod according to claim 6, wherein the contact electrode is formed tocover a top surface and side surfaces of the contact supporting part andconnected to the second electrode.
 8. The method according to claim 7,wherein the step of forming the contact electrode includes: spreadingthe conductive polymer material on the thin film transistor array wherethe contact supporting part is formed; moving a mold having a groove tocover the contact supporting part within the groove; solidifying theconductive polymer material between the groove and the contactsupporting part; and removing the mold.
 9. The method according to claim8, wherein the step of moving the mold includes moving the mold to be incontact with the thin film transistor array.
 10. The method according toclaim 8, wherein the step of solidifying the conductive polymer materialincludes performing at least one of a thermosetting process, a lightcuring process, a photo polymerization reaction process, and a heattreatment.
 11. The method according to claim 8, further comprisingsurface-treating the mold to be repulsive to the conductive polymermaterial.
 12. The method according to claim 7, wherein the step offorming the contact electrode further comprises: distributing theconductive polymer material on the contact supporting part by a supplyroller; and applying heat to the conductive polymer material so that theconductive polymer material is formed to cover the contact supportingpart by a thermal flow.
 13. The method according to claim 7, wherein thestep of forming the contact electrode further comprises: printing theconductive polymer material at a topside of the contact supporting part;applying heat to the conductive polymer material so that a portion ofthe conductive polymer material at the top side of the contactsupporting part flows down to cover a sidewall of the contact supportingpart.
 14. The method according to claim 13, wherein the step of applyingthe heat includes applying heat to the conductive polymer material sothat a portion of the conductive polymer material at the top side of thecontact supporting part flows down to cover the entire sidewall of thecontact supporting part and contact the thin film transistor array. 15.The method according to claim 1, further comprising bonding the firstand second substrates together by a sealant.